Q about mallet 75 wp, merit (or any imid 75% product) on root aphids?

I discovered root aphids and hit them with Mallet 75 WP (75% Imidacloprid). After hours of searching, I finally found a recommended dose of 2.5ml per 5 gallons water. (thoughts regarding that dosage?)

I watered all of my plants heavily to get a good saturation of the mallet. I did this 2 days ago. Today, I checked my soil and was still able to see aphids crawling around in my soil when i agitate the surface. I can see these with my plain eyes. I attempted to microscope them, and although they move quickly when I isolate them from the soil, I am 95% confident that they are root aphids. I thought the Mallet was an instant knock down. Is this not the case? How long does imid take to work?

Please only respond if you have experience with any 75% imid product on aphids or similar pests.

Well, I just discovered they were actually fungus gnats all along, and the "aphids" i see still crawling around after the mallet, well they are "Hyposaspis miles" - predatory soil mites that are seeking out fungus gnat larva to chow on. hopefully the mallet nuked everything it could and the mite population should get under control on its own once it runs out of food.